string(320) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%BD%91%E7%AB%99%E9%80%9A%E8%BF%87%E4%BC%98%E5%8C%96%E6%99%AE%E9%80%9A%E5%85%B3%E9%94%AE%E8%AF%8D%E4%B9%9F%E8%83%BD%E8%8E%B7%E5%BE%97%E5%A4%A7%E9%87%8F%E6%B5%81%E9%87%8F => Received HTTP code 403 from proxy after CONNECT"
网站通过优化普通关键词也能获得大量流量
